What will be the approximate pH of the final solution in complete neutralisation of a strong acid and a strong base?
Answer and explanation
Correct answer: Seven
A strong acid supplies H⁺ ions and a strong base supplies OH⁻ ions. During complete neutralisation, they combine in equal effective amounts: H⁺ + OH⁻ → H₂O. The remaining ions form a neutral salt when the acid and base are suitably matched, so at about 25°C the final solution has pH close to 7. Thus option A is correct; pH 3 or 11 would indicate excess acid or base.
Frequently asked questions
What is the correct answer to this question?
Seven
Why is this the correct answer?
A strong acid supplies H⁺ ions and a strong base supplies OH⁻ ions. During complete neutralisation, they combine in equal effective amounts: H⁺ + OH⁻ → H₂O. The remaining ions form a neutral salt when the acid and base are suitably matched, so at about 25°C the final solution has pH close to 7. Thus option A is correct; pH 3 or 11 would indicate excess acid or base.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Acids, Bases, and Salts.
